For this ideally you will need a medium to large straight-sided frying pan.
Remove sinews and fat from pork. Cut into 1 1/2 inch pieces.
Put the paprika and flour into a medium size plastic bag and toss the pork to coat it.
Heat oil in pan, add the butter. Add the pork chunks and fry until sealed and then remove.
Toss the chopped onion in the remainder of the paprika and flour and tip the lot into the frying pan.
Remove from heat add sherry to deglaze and then add the stock (made with the water and stock cube) and tomato purèe
Return to heat and simmer until thick.
Season with the freshly ground pepper (please note you may need some salt but there is usually enough in the stock cube).
Return the pork cover and simmer for 30 to 40 minutes.
Add the mushrooms for the final 10 minutes of cooking time
Blend the cornflour with 2 tablespoons of cold water add to the pan and bring up to boil.
Remove from heat and blend in the cream.
Garnish with triangles of fried bread and sprigs of parsley, rosemary or thyme.
Serve with salad potatoes and whole green beans.